std::recursive_timed_mutex::try_lock_for - cppreference.com (original) (raw)

| template< class Rep, class Period > bool try_lock_for( const std::chrono::duration<Rep, Period>& timeout_duration ); | | (since C++11) | | ------------------------------------------------------------------------------------------------------------------------------------------------------- | | ------------- |

Tries to lock the mutex. Blocks until the specified duration timeout_duration has elapsed (timeout) or the lock is acquired (owns the mutex), whichever comes first. On successful lock acquisition returns true, otherwise returns false.

If timeout_duration is less or equal timeout_duration.zero(), the function behaves like try_lock().

This function may block for longer than timeout_duration due to scheduling or resource contention delays.

The standard recommends that a std::steady_clock is used to measure the duration. If an implementation uses a std::system_clock instead, the wait time may also be sensitive to clock adjustments.

As with try_lock(), this function is allowed to fail spuriously and return false even if the mutex was not locked by any other thread at some point during timeout_duration.

Prior unlock() operation on the same mutex synchronizes-with (as defined in std::memory_order) this operation if it returns true.

A thread may call try_lock_for on a recursive mutex repeatedly. Successful calls to try_lock_for increment the ownership count: the mutex will only be released after the thread makes a matching number of calls to unlock().

The maximum number of levels of ownership is unspecified. A call to try_lock_for will return false if this number is exceeded.

[edit] Parameters

[edit] Return value

true if the lock was acquired successfully, otherwise false.

[edit] Exceptions

Any exception thrown by timeout_duration (durations provided by the standard library never throw).

[edit] Example

Possible output:

[0] failed failed failed [3] failed failed success [2] failed success failed [1] success failed success

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

[edit] See also

| | locks the mutex, blocks if the mutex is not available (public member function) [edit] | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | | tries to lock the mutex, returns if the mutex is not available (public member function) [edit] | | | tries to lock the mutex, returns if the mutex has beenunavailable until specified time point has been reached (public member function) [edit] | | | unlocks the mutex (public member function) [edit] |